Anti-sweep device



1961 F. D. YARNALL 2,966,852

. ANTI-SWEEP DEVICE Filed Sept. 14, 1951 2 Sheets-Sheet 1 FIG.2.

INVENTOR. F. D. YARINALL ATTYS.

United States Patent ANTI-SWEEP DEVICE Frank D. Yarnall, Hyattsville, Md., assignor to the United States of America as represented by the Secretary of the Navy Filed Sept. 14, 1951, Ser. No. 246,697

9 Claims. (Cl. 102-15) (Granted under Title 35, US. Code (1952), sec. 266) The present invention relates to moored mines and more particularly to an anti-sweep device for such mines.

As is well-known in the art, moored mines are secured to an anchor by means of a cable of measured length determined by a plummet mechanism in order to maintain the mine at a predetermined depth of submersion. When it is desired to sweep a body of water where the presence of a mine field is suspected, a sweep wire or cable is towed in the usual manner at a considerable depth below the estimated submerged depth of the mines and as a mooring cable is contacted by the sweep wire, the wire rides up the cable a sufficient distance to form a kink in the mooring cable by the pulling force of the sweep Wire, thus breaking the cable and freeing the mine from the anchor. The mine rises to the surface of the water and is disposed of.

In order to prevent such sweeping the device of the present invention is mounted on the mooring cable of a moored mine, the device being provided with apparatus for the locking thereof in response to hydraulic pressure to the mooring cable at a predetermined depth as the mine and anchor are planted in the water, such depth being sufficient to prevent the formation of a kink in the cable prior to the severance of the wire by the cutters of the present device. The device of the present invention is provided with jaws having cutting edges whereby the sweep wire is severed when the wire enters the jaws and is wedged between the angular cutting edges thereof.

An object of the present invention is to provide a new and improved mechanism for preventing the sweeping of moored mines.

Another object is to provide an anti-sweep mechanism for moored mines which will reach in an efiicacious manner a predetermined depth of submergence along the mooring cable of a mine.

A further object is to provide an anti-sweep mechanism for a moored mine which is locked against movement in the operative position on the mooring cable of the mine in a positive manner.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a view of the device of the present invention secured at a predetermined depth to the anchor cable of a moored mine and showing a sweep wire engaging the device;

Fig. 2 is a side elevation of the device of the present invention mounted on a mooring cable;

Fig. 3 is a top plan of the device, parts being broken away and the cable being shown in section;

Fig. 4 is a sectional view taken along line 44 of Fig. 3;

Fig. 5 is a view similar to Fig. 3 and showing the setting for operation at a shallower depth than that of Fig. 3; and

"ice

Fig. 6 is a view similar to Fig. 3 and showing the clamping arms in gripping engagement with the cable.

Referring more particularly to the drawings wherein like numerals indicate like parts throughout the several views, 10 indicates a mine anchor having a plummet 11, the anchor having mine 12 attached thereto by a length of mooring or anchor cable 13. As shown in Fig. 1 the anchor 10 is resting on the bed of a body of water, the mine 12 having a predetermined depth of submergence as measured by the plummet 11 and control mechanism therefor (not shown). The anti-sweep device of the present invention is indicated generally at 14 and is shown particularly in Fig. 1 as being mounted on the mooring cable 13.

The anti-sweep device 14 comprises a circular plate 15 having a plurality of depending bifurcated outer leg portions 16 welded or otherwise secured thereto adjacent the periphery thereof as at 17. Inwardly spaced from the outer leg portions is a plurality of depending bifurcated inner leg portions 18 also welded to the plate 15 as at 19. Each pair of leg portions 16 and 18 forms a pair of cutter receiving sockets which have a pair of knife-edged cutters 21, 22 mounted therebetween and removably secured by screws 23. The cutters 21 and 22 have formed in the cutting edge 24 thereof, a plurality of serrations or notches 25. The cutters 21 and 22 abut adjacent the upper ends thereof and are mounted in the leg members 16 and 18 at divergent angles to provide a wedge-shaped mouth 26 therebetween and into which the sweep wire 27 will move as the wire rides up cable 13 during a sweeping operation as will be hereinafter more fully described.

A pair of spacers 28 is positioned between each pair of outer leg portions 16. The spacers 28 and the leg portions 16 are welded or otherwise secured together as at 29. The inner leg portions are secured at the vertical juncture thereof by welding or other means as at 31. Thus a rigid frame is provided for the reception of the cutters 21 and 22. It is, of course, understood that the aforedescribed frame member may be formed of a single casting or otherwise constructed without departing from the spirit of the invention.

The plate 15 is provided with an axially located hub 32 extending from the top surface thereof, the hub having an internally threaded axial bore 33. The bore 33 receives the reduced threaded shank 34 of the ball locl-; ing device indicated generally at 35 and having an enlarged head portion 36. The ball locking device 35 has provided therein a smooth axial bore 37 for receiving the anchor cable 13. A plurality of diagonal bores 38 communicate with axial bore 37 at the lower end thereof, bores 38 receiving respectively locking balls 39 whereby the anti-sweep device 14 is permitted to move down the cable 13 and is prevented from moving up the cable 13.

A pair of cylinders 41, each having an open end and a closed end, are secured to the top of plate 15 by screws 42. Respectively mounted within the bores 43 of cylinders 41 are pistons 44 having circumferential grooves 45 containing O-ring gaskets 46 to prevent leakage of water past the pistons and into the cylinder bores 43. Interposed between the pistons 44 and the closed end of each of the cylinders 41 are nested pairs of compression springs comprising inner springs 47 and outer springs 48. Retainer rings 49 are mounted in grooves adjacent the open end of bores 43 to retain pistons 44 therein against the action of the springs 47, 48.

Pistons 44 are provided with fixed connector studs 51 at the outer ends thereof. Studs 51 have pivotally connected thereto as at 52 curved links 53. Links 53 are pivotally connected to serrated lever members 54, the serrations thereof being indicated at 55.

A ring member 56 is fitted around the hub 32 and has a set screw 57 threadedly mounted therein to engage the hub and set the ring 56 in rotationally adjusted position. Levers 54 are pivotally mounted at diametrically opposed points on the ring 56 as shown at 58. Levers 54 are provided with offset curved portions 59 to clear the walls of cylinders 41 as clearly shown in Fig. 6.

In order to set the pivot points 58 of levers 54 in a manner to grip the mooring cable 13 at a predetremined depth of submersion, an indicator or pointer 61 is fixed to ring 56, a graduated scale 62 being mounted for calibration as at 63 on plate 15. The scale 62 is preferably marked in feet of submersion. The levers 54 may be provided with reinforcing ribs 64 to prevent bending thereof.

It is, of course, understood that the levers 54 are arranged to move into gripping engagement with the cable 13 at a predetermined depth of submersion governed by the hydrostatic pressure prevailing at such depth, the spring rate of springs 47 and 48 and the setting of the pivot points 58 in accordance with scale 62.

In operation the anti-sweep device of the present invention is mounted on the mooring cable 13 of the mine 12 between the mine and the anchor 10. As the mine is planted the anchor falls toward the bed of a body of water, the mine remaining at the surface. The plummet falls from the anchor at a faster rate than the rate of fall of the anchor. When a predetermined amount of plummet line has been let out the line is locked and the distance between the plummet and the anchor remains constant until the plummet strikes the bed of the body of water, whereupon, the anchor cable feed drum is locked, the anchor drawing the mine to a predetermined depth of submersion as measured by the plummet line.

During the aforedescribed operation, the device 14 moves down the cable 13. When the device 14 reaches a predetermined depth, water pressure acting on pistons 44 causes the pistons to move inwardly in the cylinders 41 against the action of springs 47 and 48. Pistons 44 pivot levers 54 towards cable 13, through links 53, until the cable is firmly gripped between the two levers. The strain of maintaining the device 14 at the locked position on cable 13 against the lifting action of the sweep wire is taken up by the ball locking device 35 which locks to prevent upward movement of the device and does not impede the device in the downward movement thereof.

It is readily seen that the device of the present invention will sever a sweep wire as the wire rides up the cable 13, the sweep wire becoming wedged between adjacent notched knife edges of blades 21 and 22, thus tending to lift anchor 10, the weight of the anchor plus the wedging action being sufficient in conjunction with the knife edges to sever the sweep wire.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An anti-sweep device mounted on the anchor cable of a moored mine comprising, in combination, a frame member having a hub with an axial bore therethrough for receiving said cable and having serrated knife members for engaging and cutting a sweep wire, a pair of cylinders mounted on said frame at diametrically opposed sides of said bore and each having an open and a closed end, a pair of spring biased pistons respectively mounted in said cylinders, a ring member rotatively mounted on said hub, a set screw mounted in said ring member for engaging the hub to lock the ring member thereto in a selected adjusted position, a pair of toothed gripping levers respectively pivoted to said ring member at diametrically opposed points, a pointer secured to said ring, a scale secured to said frame in registry with said pointer whereby the pivot points of said levers may be set rotatively with respect to the frame, and respective link connections between said levers and said pistons for moving the levers into gripping engagement with the anchor cable as the frame descends on the cable until a hydrostatic pressure is reached corresponding to a selected depth of submersion.

2. Apparatus for severing a sweep wire comprising, in combination, a subfloating marine mine, an anchor for said mine, a cable connecting said mine to said anchor, a frame member slideably mounted on said cable, a ball locking means mounted on said frame for preventing upward movement of said frame, a pair of levers mounted on said frame for engaging opposite sides of said cable to provent movement of the frame with respect to the cable, hydrostatic means connected to said levers for moving the levers into engagement with the cable when the frame has moved down the cable toa predetermined depth of submersion, and cutter means on said frame for engaging and severing said sweep wire as the wire moves up the cable during a sweeping operation.

3, A device for preventing the sweeping of a moored marine mine by a sweep wire comprising, in combination, a frame member having a top disk member and a plurality of knife receiving sockets, a plurality of pairs of serrated knife members supported by said frame member, each of said pairs having the cutting edges thereof in spaced adjacency at the lower ends thereof to form a sweep wire receiving mouth and meeting at the upper ends thereof to sever said wire as the wire wedges therebetween, a central bore in said disk member for receiving the anchor cable of said mine, ball locking means secured to said disk member and surrounding said cable to prevent movement of the frame member in an upward direction, spring-biased pressure operated means mounted on said disk member, and a pair of levers mounted adjacent said bore and responsive to said pressure operated means to fixedly grip said cable therebetween as the device reaches a predetermined depth of submersion.

4. A device for preventing the sweeping by a sweep wire of a marine mine moored by an anchor cable comprising, in combination, a frame member having cutter means secured thereto, said frame member being slideably mounted on the anchor cable of said mine, ball locking means mounted on said frame and engaging the cable to prevent upward movement of said frame, cable gripping means mounted on said frame, and hydrostatically operated means operatively connected to said cable gripping means for causing the cable gripping means to engage the cable in such manner to prevent further movement of the frame beyond a predetermined depth of submersion as the frame moves down the cable.

5. A device for preventing the sweeping by a sweep wire of a marine mine moored by a mooring cable comprising, in combination, a frame member mounted for sliding movement on the mooring cable of said mine, means attached to said frame for preventing movement of the frame member toward the mine, a pair of gripping members mounted on said frame for gripping said cable, spring-biased pressure responsive means mounted on the frame member for actuating said gripping members at a predetermined depth of submersion, and a plurality of serrated knife members mounted in said frame and having wedge-shaped openings therebetween for engaging and cutting said sweep wire as the sweep wire moves up the anchor cable during a sweeping operation.

6. An anti-sweep device for a subfloating marine mine moored by an anchor cable comprising, in combination, a frame member having cutter means for cutting a sweep wire and slideably mounted on the anchor cable of said mine, spring biased hydrostatic means mounted on said frame, a pair of serrated levers mounted on the frame member actuated by said spring biased hydrostatic means for locking the frame to the cable at a predetermined depth of submersion as the device moves down the cable during a mine laying operation, and ball locking means for preventing movement of the device in an upward direction with respect to the cable.

7. An anti-sweep device for a subfloating marine mine moored by an anchor cable comprising, in combination, a frame member having cutter means for cutting a sweep wire and slideably mounted on the anchor cable of said mine, cable gripping members mounted on said frame member, spring-biased hydrostatic means mounted on said frame member for actuating said cable gripping members to grip the anchor cable, and depth selecting and indicating means mounted on said frame member for preselecting the depth of submersion at which said springbiased hydrostatic means will actuate said cable gripping members. i

8. Anti-sweep apparatus for a marine mine moored by an anchor cable comprising, in combination, a frame member having a disklike top portion, said top portion having a central orifice to receive the anchor cable of said mine and a plurality of opposed cutter-receiving socket portions depending therefrom around the periphery of said disklike portion, a plurality of serrated angularly disposed cutter members secured in said sockets, said cutter members being mounted in opposed pairs and having the cutting edges thereof spaced at the bottom and in abutting engagement at the top, said pairs of cutter members receiving and severing a sweep wire as the wire moves up the anchor cable, a pair of spring biased pressure responsive devices mounted on said frame, hydrostatically controlled gripping means operatively connected to said devices for preventing the descent of said apparatus along the cable beyond a predetermined depth of submersion, and ball locking means for preventing up- Ward motion of said apparatus along the cable.

9. A device for preventing the sweeping by a sweep Wire of a marine mine moored by a mooring cable comprising, in combination, a frame member slideably mounted on the mooring cable of said mine, cable gripping members mounted on said frame, hydrostatic pressure responsive means mounted on the frame and operatively connected to said gripping members for causing the gripping members to grip the cable when said frame member has reached a predetermined depth of submer sion, and a plurality of serrated knife members supported by said frame member for cutting said sweep wire as the sweep wire is engaged thereby, each of said knife members being detachably secured to said frame.

References Cited in the file of this patent UNITED STATES IPATENTS 1,304,549 Du Pont May 27, 1919 FOREIGN PATENTS 360,634 Italy July 1, 1938 

